TBA (25S140)

The “right” biopsy protocol for microscopic colitis: reduced workload and carbon footprint while maintaining diagnostic accuracy

Author(s)

Leung, E; Alshareefy, Y; Costigan, C; Sihag, S; Kripakaran, D; Connolly, Y; O'Donnell, S; Breslin, N; O'Connor, A; Ryan, B; Zaheer, A; Cretu, I; O'Hara, F ; McNamara, D

Department(s)/Institutions

Tallaght University Hospital, Dublin, Ireland; Trinity Academic Gastroenterology Group, Trinity College, Dublin, Ireland; Naas General Hospital, Kildare, Ireland;

Introduction

Histological findings of microscopic colitis are patchy with potential for missed diagnoses. While current guidelines recommend biopsies from the right and left side of the colon, the optimal approach is uncertain.

Aims/Background

To interrogate biopsies in patients with microscopic colitis to improve biopsy protocols.

Method

We conducted a multi-centre retrospective cohort study of index colonoscopies in microscopic colitis patients over a 14 year period. We recorded demographics, symptoms, total number and location of biopsies, and whether they revealed features of lymphocytic or collagenous colitis.

Results

228 index colonoscopies were included, 64%(145/228) lymphocytic colitis, 36%(83/228) collagenous colitis. Median age at diagnosis was 60(IQR 48-72), 27%(61/228)<50yrs. 71%(162/228) female, similar for both subtypes. Of interest, males were older than females at time of diagnosis (62 vs 56, p=0.03). Symptoms were known in 86%(196/228), 98%(192/196) had diarrhoea. In 150 subjects who had any biopsy identified from the right colon, 100% had microscopic colitis features there and only 2%(3/150) had a patchy distribution there. While some subjects had positive right colon biopsies with negative left colon biopsies (10%, 13/136), the converse was not true. Regarding containers identified as being from the right or left colon, those from the left were more likely to be negative (9%(17/199) vs 2%(4/209), OR 4.79, p=0.0025).

Conclusions

These findings support the need for a full colonoscopy for patients of all ages presenting with diarrhoea. In the era of green endoscopy, our data supports a protocol of taking biopsies from at least two sites in the right colon only, processed in a single container.